Mine roof supports

ABSTRACT

The invention is for a mine roof support comprising a roof engaging structure or canopy mounted on hydraulic prop means and having an extension bar which can be advanced and set to the roof, following the passage of a mineral mining machine along the mineral face, so as to provide immediate roof support over the face conveyor and/or adjacent the coal face. A hydraulic ram for advancing the extension bar is connected to said bar by a lever device having a part which engages an abutment on the roof engaging member or canopy, at a predetermined amount of extension of the extension bar, so as automatically to cause the extension bar to tilt or move upwardly and be set against the roof by said advancing ram.

ilnited States Patent 11 1 Stevenson 1 May 15, 1973 [54] MINE ROOF SUPPORTS FOREIGN PATENTS OR APPLICATIONS lnvemorl James y Stevenson, Wigan, 882,933 11/1961 Great Britain ..6l/45 D gland 1,313,208 11/1962 France ..61/45 1) 1,918,048 10 1970 Germany ..61/45 1) [73] Assgnee' 5 :22, mbso 1,037,734 8/1966 Great Britain ..61/45 D [22] Filed: Nov. 23, 1971 Primary Examiner-Dennis L. Taylor App]. No.: 201,444

Attorney- Berman, Davidson & Berman V [57] ABSTRACT The invention is for a mine roof support comprising a roof engaging structure or canopy mounted on hydraulic prop means and having an extension bar which can be advanced and set to the roof, following the passage of a mineral mining machine along the mineral face, so as to provide immediate roof support over the face conveyor and/or adjacent the coal face. A hydraulic ram for advancing the extension bar is connected to said bar by a lever device having a part which engages an abutment on the roof engaging member or canopy, at a predetermined amount of extension of the extension bar, so as automatically to cause the extension bar to tilt or move upwardly and be set against the roof by said advancing ram.

5 Claims, 8 Drawing Figures PATENTEDHAYISIQYS v 3,

SHEET & 0F 6 PATENTEDHAY 1 5197s SHEET 8 OF 6 Q NGE NP NN MINE ROOF SUPPORTS This invention is for improvements in or relating to mine roof supports of the kind (hereinafter referred to as the kind specified) comprising a roof engaging structure or canopy mounted on hydraulic prop means and having an extension bar which can be advanced and set to the roof, following the passage of a mineral mining machine along the mineral face, so as to provide immediate roof support over the face conveyor and/or adjacent the coal face. A hydraulic ram, incorporated, for example, in the roof engaging member or canopy, may be provided for advancing the extension bar.

According to the present invention there is provided a mine roof support of the kind specified wherein the extension bar and the roof engaging member or canopy by which it is slidably supported have co-operating parts which at a predetermined amount of extension of the extension bar come into engagement so as automatically to cause the extension bar to tilt or move upwardly and be set against a roof.

According to a further feature of the present invention there is provided a mine roof support of the kind specified wherein a means for advancing the extension bar is connected to said extension bar by a device which, when said device engages an abutment at a pre determined amount of extension of the extension bar, automatically causes the extension bar to tilt or move upwardly and be set against a roof by said advancing means.

In preferred embodiments of the invention the arrangement is such that the extension bar is set to the roof automatically following achievement of substantially its position of maximum extension. Conveniently said device is a lever having a pivot pin, between its ends, for attachment to the advancing means and one of its ends pivotally attached to the extension bar and its other end adapted to engage the above mentioned abutment. Said lever may have the form of a shackle or link.

The means for advancing the extension bar may be adapted for manual operation but preferably is a hydraulic ram.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying semi-diagrammatic drawings in which:

FIG. 1 is a side elevation of an upper part or canopy of a self-advancing mine roof support,

FIG. 2 is a plan view of FIG. 1,

FIG. 3 is a fragmentary sectional view on the line X--X of FIG. 2,

FIGS. 4 and 5 are detail views showing how a ram, for operating the extension bar is mounted in the canopy,

FIG. 6 is a perspective view of the device by which the ram is coupled to the extension bar, and

FIG. 7 shows modification.

On the drawings the invention is shown as applied to a self-advancing mine roof support of the kind comprising a base, one or more hydraulically extensible props mounted on said base and a roof engaging structure or canopy mounted on said props.

Referring to the drawings the reference numeral 10 indicates a cantilever extension of the above mentioned canopy or roof engaging structure, said extension being pivotally connected to the forward end of said canopy or roof engaging structure by pivots indicated at 10a. The cantilever extension 10 is supported on hydraulically extensible, telescopic props or legs 11 (see FIG. 2) mounted in said base in the usual way.

Slidably supported within and by the canopy extension 10 is an extension bar 12, extension and retraction of this bar being effected by a hydraulic ram 13 also housed in the underside of the canopy extension.

The ram 13 is pivotally supported from the canopy extension by trunnions 14, on its cylinder, which are journalled in bearing brackets 15 (see FIGS. 4 and 5) on the underside of the canopy extension.

The piston rod 16 of the ram 13 is coupled (see FIGS. 3 and 6) to the extension bar 12 by a lever in the form of a shackle-like device or link 17, pivotally connected to said piston rod and the extension bar 12 by pivot pins 18 and 19 respectively.

An abutment or stop 20, for the shackle or link 17 is provided at or towards the forward end of the canopy extension 10.

As the extension bar 12 is advanced the upper part of the shackle 17 eventually (i.e. following achievement substantially of its position of maximum extension) engages the abutment 20 so that the shackle is tilted rearwardly about the pivot 18 and the extension bar is tilted upwardly, on its trunnion-like pivots 21 (see FIG. l) which slidably and partially supports it in the canopy 10. Thus, when fully extended the extension bar is automatically brought to a roof engaging and supporting condition. One advantage of this is that a miner is not required to enter the area under newly exposed roof to set the extension bar manually e.g. by driving in wedges.

As above described, in the particular embodiment of the invention shown on the drawings the canopy extension 10 is a cantilever pivotally connected at its rear to a further roof engaging structure or canopy. The invention can, however, be used in connection with various forms of supports or checks of the kind specified.

In the modification shown in FIG. 7 the lever 17 is extended and the piston rod 16, of the ram 13 is connected to it at 180. Thus, the lever provides mechanical advantage for the setting of the extension bar to the roof. For the advance of the extension bar the lever 17 bears against the stop-part 12a at the rear end of said bar.

I claim:

1. In a mine roof support the combination of a roof supporting member, an extension bar slidably supported in said roof supporting member for forward advancement relatively thereto, means for halting said extension bar at its position of maximum extension, a hydraulic ram means, for effecting such advancement of said extension bar, connected to the extension bar by a lever having a pivotal connection to the ram and a pivotal connection to the extension bar, and an abutment positioned on the roof supporting member so as to be engaged by an arm of said lever, when the extension bar reaches its position of maximum extension, whereby further advancement of the ram is operative only to tilt the forward end of the extension bar upwardly into a roof supporting condition.

2. A combination according to claim 1 wherein said lever is of shackle or link-like form.

3. A combination according to claim 1 in which the lever has its pivot arranged so as to provide mechanical advantage for the setting of the extension bar to the roof.

4 lever has one of its ends pivotally connected to the ram, its other end positioned for engagement by said abutment and a pivotal connection to the extension bar intermediate said ends. 

1. In a mine roof support the combination of a roof supporting member, an extension bar slidably supported in said roof supporting member for forward advancement relatively thereto, means for halting said extension bar at its position of maximum extension, a hydraulic ram means, for effecting such advancement of said extension bar, connected to the extension bar by a lever having a pivotal connection to the ram and a pivotal connection to the extension bar, and an abutment positioned on the roof supporting member so as to be engaged by an arm of said lever, when the extension bar reaches its position of maximum extension, whereby further advancement of the ram is operative only to tilt the forward end of the extension bar upwardly into a roof supporting condition.
 2. A combination according to claim 1 wherein said lever is of shackle or link-like form.
 3. A combination according to claim 1 in which the lever has its pivot arranged so as to provide mechanical advantage for the setting of the extension bar to the roof.
 4. A combination according to claim 1 wherein the lever has one of its ends pivotally connected to the extension bar, its other end adapted to engage said abutment and a pivotal connection to the ram between said ends.
 5. A combination according to claim 1 wherein the lever has one of its ends pivotally connected to the ram, its other end positioned for engagement by said abutment and a pivotal connection to the extension bar intermediate said ends. 